Thai authorities have arrested more than 100 Sri Lankan Tamils this week because of fears they might be taken illegally to destinations such as Canada and Australia. Those arrested are being held in an immigration detention center and face court proceedings for immigration violations.

South Asian diplomatic sources say Thai authorities made the arrests because of a growing number of Sri Lankan Tamils arriving on tourist visas. Of the 130 arrested this week, more than 60 are women and children and many have lived in Thailand up to three years.

Human rights groups many have applied to the United Nations High Commissioner for Refugees for asylum.

Thai Foreign Ministry spokesman Thani Thongphakdi says the arrests were part of normal efforts to enforce immigration laws and prevent people smuggling.

"As you know the Thai authorities have been working closely with the authorities of other friendly countries on the issue of human trafficking and the arrests made were a law enforcement effort to address this issue," Thani said. "So everything was carried out with a view to enforce immigration laws."

Thani says each detainee's visa status will be assessed following their court appearances. Most face charges of overstaying their visas.

Human rights groups criticized the Thai government and UNHCR over the arrests. Sunai Pasuk, a representative for Human Rights Watch in Thailand, says the Tamils should not be deported back to Sri Lanka.

"The Thai government shows no respect in their international commitment to protect asylum seekers. So this may end up being another sad case of people who deserve to be put under international protection but end up being deported by the Thai state to the place where they will be in danger," says Sunai Pusak.

Benjamin Zawacki, a researcher with Amnesty International, called on the UNHCR to show its support for detainees who have applied for asylum.

"The Thais have given no indication that these people have definitely been involved with the LTTE [the Sri Lankan rebel group, the Liberation Tigers of Tamil Eelam] or smuggling or trafficking," Zawacki said. "So it's clear at this point that UNHCR needs to support its own protection mandate in voicing support for these people."

In August, Canadian authorities detained a Thai-registered ship with almost 500 Tamil asylum seekers on board. Officials in Canada were concerned that some on board had links to the Liberation Tigers of Tamil Eelam, which many countries consider a terrorist group. The Sri Lankan army crushed the Tamil Tiger forces last year after several decades of fighting for independence.

Australia also has seen a rising number of Tamil asylum seekers trying to arrive by boat.

South Asian diplomatic sources say those detained could not afford the thousands of dollars that smugglers charge to take them to Canada or Australia.